1. Field of the Invention
The present invention concerns new flexible sachets for transporting bio-pharmaceutical fluid products and a method of manufacturing them.
2. Description of the Prior Art
U.S. Pat. Ser. No. 350,080 describes sachets which can be used for cellular culture media and their rigid transportation container.
The bio-pharmaceuticals industry, understood in the broadest sense, is increasingly using flexible sachets with capacities in the range 20 liters to 2,000 liters and more, in particular bio-compatible sachets, to transport fluids use in the industry, such as culture media, cellular cultures, buffer solutions, artificial nutrient liquids, blood products or derived products such as plasma.
Sometimes the products contained in such sachets are used thousands of kilometers from the place where the sachets were filled. These products are often extremely valuable in financial terms and often extremely valuable in terms of the health of persons because they can be used to manufacture medication for human use, for example. It is therefore essential for such sachets to reach their destination safely, filled with the liquid with which they were initially filled, and free of contamination.
Flexible sachets of the above kind are subject to many kinds of stress during transportation: acceleration, braking, tossing, shaking, vibration, etc. and therefore to many forces including shear forces which tend to deteriorate the film from which they are made, especially at sensitive locations such as folds. Consequently these various stresses frequently lead to weakening, rupture or piercing of the sachets.
It must be remembered that sachets of the above kind intended to contain the previously mentioned liquid products and media are by their very nature provided with a number of access ports enabling their content to be filled, drawn off, mixed, etc., for example, and usually with a number of tubes installed at some or all of these access ports. The tubes are themselves often fitted with one or more rigid material devices such as valves, filters or clamps which can contribute to abrasion of the upper part of the sachets when they are transported over long distances. A hole in the top of a sachet can be just as serious as one elsewhere, for example in the situation of transporting sterile contents.
This is why it would therefore be desirable to have a sachet for transporting bio-pharmaceutical liquids with a volume of 50 liters or more which in addition to the usual qualities of such sachets, i.e. biocompatibility, sterilizability, impermeability to gases and in particular to oxygen, would be particularly resistant to transportation over long distances and easy to manufacture.
Sachets for transporting bio-pharmaceutical liquids in the form of bellows with walls constructed by manually welding three separate independent films are known in themselves.
Sachets of the above type are sold by HyClone Laboratories, for example. They have capacities in the range 1 liter to 1,000 liters, for example. However, when transported over long distances, given the many stresses to which the sachets are subjected, a number of them are lost because of leaks.